Android-画布不显示

Question

I have researched this on Stack Overflow, but I didn't find the fix to my problem. I have a view that contains the code for a vertical, yellow line on the screen. I have an activity that creates the dialog whose content view is an instance of the view. The dialog pops up, but the yellow line doesn't show. What am I missing? Here is my code:

View :

 public guidelines(Context context) {
    super(context);
    int x = this.getWidth()/2 - 3;
    int y = this.getHeight();
    shape = new ShapeDrawable(new RectShape());
    shape.getPaint().setColor(Color.YELLOW);
    shape.setBounds(x, 0, x+6, y);

}

@Override
protected void onDraw(Canvas canvas) {
    shape.draw(canvas);
}

Layout for the View :

    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res/---
    android:layout_width="match_parent" android:layout_height="match_parent">

    <!-- <--- android:background="#ccc"
        android:layout_width="300dp" android:layout_height="300dp" android:paddingLeft="20dp"
        android:paddingBottom="40dp" app:exampleDimension="24sp" app:exampleColor="#33b5e5"
        app:exampleString="Hello, guidelines" /> -->

    < ---
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/frame"/>

</FrameLayout>

Dialog Calling Code :

final Dialog dialog = new Dialog(this);
    dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
    dialog.getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));
    guidelines g = new guidelines(this);
    dialog.setContentView(g);
    dialog.show();

Thanks.

Answer 1

It was better to just use the drawRect function of the canvas. I did that and it worked.